package cn.tedu.egarticle.base.filter;


import cn.tedu.egarticle.pojo.vo.UserVO;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@Slf4j
@WebFilter(filterName = "MyFilter", urlPatterns = {"/v1/user/*"})
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.debug("过滤器初始化方法");
    }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        log.debug("进入登录状态校验的过滤器");
        //HttpServletRequest是ServeletRequest的子接口，所有可以强转为HttpSerletRequest
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //获取session 会话对象
        HttpSession session = request.getSession();
        //获取会话标识
        UserVO userVO = (UserVO) session.getAttribute("user");
        //判断会话标识是否为空
        if(userVO != null){
            //有此行代码代表放行
            //无此行代码，代表拦截
            filterChain.doFilter(request,response);
        }else {
            response.sendRedirect("/login.html");
            //因为无filterChain.doFilter(request,response);，代表拦截
            //
        }
    }
    /**
     * 过滤器销毁时执行的方法,比如：
     * 1.关闭数据库连接
     * 2.释放资源
     * 3.记录日志
     * 4.清理临时文件或数据
     */
    @Override
    public void destroy() {
        log.debug("过滤器销毁方法");
    }

}
